A behind-the-ear (BTE) hearing aid usually includes a behind-the-ear component to be worn behind the ear. The behind-the-ear component usually further includes a microphone for collecting sound waves and a signal processing circuit (also referred to as speech processing circuit) for processing the collected sound waves.
The sound waves may be conducted to the ear by means of a sound tube connected to the behind-the-ear component at its one end, wherein the other end of the sound tube may be coupled with an earmould. Due to different physiology of ears of different users, the earmould is usually custom made, e.g. by taking the impression of the ear, to fit into the ear canal of different users.
The sound waves may also be conducted to the ear by means of a wire, e.g. housed in a sound tube, and a speaker (which may also be referred to as a receiver in the field of hearing aids) placed in the ear canal. Such a hearing aid is also referred to as a receiver in the ear aid. For example, as shown in FIG. 1, a sound tube 102 is coupled with the speaker 104, with at least one wire 106 housed within the sound tube 102 and connecting the speaker 104 with the behind-the-ear component (not shown).
The sound tube 102 is coupled with the speaker 104 such that the speaker 104 has a fixed predefined entry position to be put into the ear canal. A dome structure 108 made of a soft material may be assembled to the speaker 104 which covers the opening of the ear canal by its large surface. The soft dome structure 108 may help to decrease the uncomfortableness, but the size, shape and position of the soft dome structure 108 may still induce pain to some part of the ear canal due to different physiology of the ear.